<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        div {
            width: 310px;
            height: 200px;
            margin: 100px auto;
            border-radius: 10px;
            background: url("img/paopao.png") top left,
                url("img/paopao.png") bottom right;
            background-color: darkseagreen;
            transition: all 2s linear;
        }
        div:hover {
            background-position: bottom left,top right;
        }
    </style>
</head>
<body>
<div></div>
</body>
</html>